Cutting dies are commonly used for manufacturing boxes, cartons, and container blanks from a sheet material such as corrugated paper board. The cutting die includes a series of cutting rules arranged in the shape of the blank to be formed. Often times, the blank will include one or more narrow slots. For example, carton blanks frequently include three narrow slots separating the flaps on the carton. Larger slots are also used to form hand holds for a carton.
When slots are formed in a blank, a narrow piece of scrap is severed from the carton. It is desirable to strip the severed scrap from the blank as the blank passes through the rotary die. In the past, resilient rubber strips made of closed cell, high density foam or gum rubber have been placed in the cavities between cutting rules to eject the blank and strip the scrap. These rubber ejectors/strippers (hereinafter "ejector") rely on the resiliency of the material to strip the scrap. The ejector is compressed during the cutting operation and subsequently expands when the cutting die is moved away from the blank. As the rubber ejector expands, the scrap is held against the anvil cylinder and stripped from the blank. Simultaneously, the corrugated is ejected off the die with the similar rubber ejectors.
The rubber scrap ejectors used in the past have been less than fully effective in stripping scrap from the blank. One way to improve performance of the scrap ejector is to increase the height of the ejector. As a general rule, the greater the height of the ejector, the more it will be compressed during cutting and the more effective it will be in stripping the scrap. However, there is a practical limit on how much the scrap ejector can be compressed, and thus, a limit on the height which can be obtained. If the scrap ejector is compressed beyond the limits of its resiliency, then the scrap ejector may be permanently deformed and its effectiveness in stripping scrap is seriously impaired.